方程x²-7=3x的根的情况为(      )

阅读理解                                                           

                                                                Table manners in America

        Don't circle your plate with your arms. If you do so, you will become the focus  (焦点)  of the table. Everyone would wonder, "Is there anything wrong with the food?" This may give a wrong message that you don't like the food or something like that.

       Don't push the plate back when finished. Leave it where it was. Do you want to let the hostess (女主人)(1)_________(know ) that you've just done a labours。

        Don't lean (倚靠) back and say "I'm through" or "I'm full". Just put the fork and knife across the plate. That's all. 

       (2)Don't cut up everything before you start to eat. Cut only one or two bites (块) at a time. Never take a huge mouthful of anything. Do you want to show how hungry you are? Don't do that. It's not so good.

        It's never good to reach across the table for anything. If the thing you want is not at hand, simply ask the nearest person for help, like "(3) Mrs. Smith, could you pass me the dish?"

材料一：1840年，英国侵略者凭借船坚利炮打开了中国的大门，开启了先进的中国人向西方学习的道路。

材料二：十月革命一声炮响，给我们送来了……开始了“以俄为师”的道路。建立农村革命根据地，开始走自己的路。

    建设有中国特色的社会主义道路，是***带领全国人民走向辉煌的利器。